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doc-src/Tutorial/Datatype/assoc
author paulson
Thu, 17 Jun 1999 10:33:43 +0200
changeset 6831 799859f2e657
parent 5851 15ce4c1c8313
permissions -rw-r--r--
expandshort
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
5851
15ce4c1c8313 New section on advanced datatypes.
nipkow
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consts   assoc :: "('key * 'val)list => 'key => 'val option"
15ce4c1c8313 New section on advanced datatypes.
nipkow
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primrec "assoc [] x = None"
15ce4c1c8313 New section on advanced datatypes.
nipkow
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        "assoc (p#ps) x =
15ce4c1c8313 New section on advanced datatypes.
nipkow
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           (let (a,b) = p in if a=x then Some b else assoc ps x)"
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